Nineteen-year-old noble Elena Valshia turns out magic-free at her coming-of-age ritual. Shamed by her fiancé and disinherited by her father, she collapses by an old well on a rainy night. The thousand-year-sealed Black Dragon King Savik breaks through the sky and swears loyalty solely to her. The outcast girl soon becomes the continent's public enemy, hunted by imperial dragon-knights and condemned by the dragon elders. A hidden lock-shaped curse mark on her neck unlocks the millennium-old conspiracy.